1. Field of the Invention
This invention relates to an LIF (low insertion force) connector having a lever member by which male and female connectors (multi-pole connectors) each having many terminals are fitted together with a low insertion force, and more particularly to such an LIF connector in which the lever member can be provisionally retained satisfactorily.
2. Background
In an LIF connector having a lever member, cam pins, formed on one of male and female connectors, are introduced respectively into cam grooves formed in the other connector, and the one connector is set on the other connector, and in this condition, the lever member is pivotally moved, thereby fitting the two connectors together with a low insertion force.
In one type of such LIF connector, when one of the male and female connectors is to be set on the other connector, the lever member is provisionally retained so as to position the cam grooves with respect to the cam pins.
A conventional LIF connector designed to provisionally retain a lever member, will now be described with reference to the drawings.
FIG. 5 shows an exploded, perspective view of the LIF connector proposed in Unexamined Japanese Patent Publication No. Hei. 5-129048. FIG. 6a is a side-elevational view showing a provisionally-retained condition of the LIF connector, and FIG. 6b is a side-elevational view showing a condition in which the provisionally-retained condition of the LIF connector is released.
In FIG. 5, a housing 111 of a female connector 110 has a reception portion 112 for a male connector 130. Vertical grooves 113 are formed respectively in opposite side walls forming the reception portion 112, and a pivot shaft 114 is formed immediately below each of the vertical grooves 113.
A lever member 120 (more fully described later) is pivotally mounted on the pivot shafts 114 through through holes 121, and as shown in FIG. 6a, a provisionally-retaining projection 115 is formed on an upper end portion of one of the opposite side walls of the housing 111, and can retainingly engage a distal end 120a of one of opposed side walls of the lever member 120 to thereby retain the lever member 120 in a provisionally-retained condition.
As shown in FIG. 5, a vertical notch 116 is formed in the one side wall of the housing 111, and is disposed between the vertical groove 113 and the provisionally-retaining projection 115.
A disengagement prevention portion 117 for preventing the disengagement of the lever member 120 is formed on the one side wall of the housing 111, and covers the provisionally-retaining projection 115 and the notch 116.
Cam grooves 122 are formed respectively in the opposed side walls of the lever member 120, and intersect the vertical grooves 113 in the female connector 110, respectively.
The male connector 130 includes a housing 131 of a rectangular shape corresponding to the reception portion 112 of the female connector 110, and cam pins 132, which can be guided by the vertical grooves 113 and the cam grooves 122, are formed respectively on opposite side walls of the housing 131.
A retainment release rib 133, corresponding to the notch 116 in the female connector 110, is formed on one of the opposite side walls of the housing 131.
The operation for fitting the male and female connectors of this conventional LIF connector together will be described with reference to FIGS. 6a and 6b.
As shown in FIG. 6a, when the distal end 120a of the one side wall of the lever member 120 is retained by the provisionally-retaining projection 115 of the female connector 110, the lever member 120 is held in the provisionally-retained condition.
In this provisionally-retained condition, open ends of the cam grooves 122 in the lever member 120 coincide respectively with open ends of the vertical grooves 113 in the female connector 110, and these open ends are positioned with respect to the associated cam pins 132 on the male connector 130.
Then, as shown in FIG. 6b, the cam pins 132 are introduced into the open ends of the associated cam grooves 122 and vertical grooves 113, and the male connector 130 is set on the female connector 110.
Accordingly, the retainment release rib 133 of the male connector 130 is introduced into the notch 116 in the female connector 110, and outwardly forces the distal end 120a of the lever member 120 retained by the provisionally-retaining projection 115.
Accordingly, the retaining engagement of the distal end 120a with the provisionally-retaining projection 115 is released (that is, the provisionally-retained condition of the lever member 120 is released), so that the lever member 120 can be pivotally moved.
Thereafter, when the lever member 120 is pivotally moved in a direction of arrow P shown in FIG. 6b, each cam pin 132 is moved along the associated cam groove 122 and vertical groove 113, so that the male connector 130 is fitted into the female connector 110.
However, in the above conventional LIF connector, the distal end 120a of the lever member 120 is forced outwardly by the retainment release rib 133 of the male connector 130, thereby releasing the retaining engagement of the distal end 120a with the provisionally-retaining projection 115. Therefore, the outwardly-forced distal end 120a deforms the disengagement prevention portion 117 disposed at the outermost peripheral portion of the female connector 110.
Accordingly, there is a disadvantage that a fixing portion for being fixed to a vehicle or the like can not be provided on the disengagement prevention portion 117 disposed at the outermost peripheral portion which is the optimum position for mounting this fixing portion.
Furthermore, if the fixing portion for being fixed to the vehicle or the like is mounted on the disengagement prevention portion 117 which can be thus deformed, the disengagement prevention portion 117 or the distal end 120a of the lever member 120 may be damaged by stresses as a result of repeated operation of the lever member 120.